Problems with CBRs

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3 months 6 days ago #2193 by kitsunebi
Replied by kitsunebi on topic Problems with CBRs
I'm sorry I can't be of any help. I honestly don't think I even understand the problem. You're asking how to extract images from a CBR, but there isn't a need to "extract" images from a CBR. You just move files into or out of a CBR the same way you move a file into or out of a folder. A CBR is just a folder of jpgs that has been RARed or ZIPed. Just upzip or unrar the CBR and you will have a folder of jpgs, after which you can easily do literally anything you could ever imagine with them. It really isn't possible to have a more flexible format to edit than having the original jpgs. And if all you want to do is delete or add images to the CBR, you can do that from within WinRAR - you don't even need to unRAR the file or even change the extension. If you want to save just certain pages to create a new CBR, you can either unRAR the CBR, open the folder, select the images you want and RAR those again to create a new CBR, or you can open a CBR normally and save whatever images you like to a folder using the CBR reader software, then RAR that folder to create a new CBR. Either way, your new files will feature the EXACT same jpgs that were in the original file, so there will never be a case of decreased quality or file bloat.

So though I don't understand exactly what it is you're having trouble doing, I suppose it's possible that as Kiwi suggested, your criteria may simply be so outside of the norm that it's unlikely that there will be a solution to your particular problem. It sounds like you've converted CBRs to PDFs in the past, so I guess the only advice I can give you is to just keep doing whatever you've been doing if you're happy with it.

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3 months 6 days ago #2194 by kitsunebi
Replied by kitsunebi on topic Problems with CBRs
Oh, and by the way, fellas, I realize that "install a new CBR reader" is not anything you're interested in doing, but just in case anyone was afraid to install CDisplayEX because of the negative comments that one guy posted to a Wikipedia chat 6 years ago...

I just downloaded and installed CDisplayEX. There is no adware or bloatware. Indeed, there is no additional software whatsoever bundled with it. And to be extra careful, I ran my malware software afterwards and there is no malware detected either. So assuming there ever was a problem with it in the past, it seems to be completely safe now.

It's not the reader I personally use, but I see nothing wrong with it whatsoever (well, aside from the fact that upon initial startup, the default is set to creating an artificial gutter shadow when in two page mode, which I hate...but some people like it, and it's easily switched off.)

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3 months 6 days ago #2199 by Kiwi
Replied by Kiwi on topic Problems with CBRs

JabbaTheGamer wrote: I apologize if these comments come off as grumpy: this was not my intention. This is just a minor complaint that got out of proportion. At first when Kiwi announced the move to CBRs I wanted to keep silent about it, but decided to speak up after Cez created this thread as I saw that I wasn't the only one here who has a preference for the PDF format. I understand that CBRs are here to stay, in addition to the fact that this is the main file format other scanning communities use (and the OGM was actually an outlier as it used PDFs until recently).


I didn't class your comments as grumpy. Indeed, I was expecting more comments about the use of CBR to arise than there actually have been!! But when kitsunebi came on board he specifically wanted his magazine submissions to stay as CBR and after getting CDisplayEX up and running and realising a lot of my misgivings over the format were a non issue I didn't really see any reason why I didn't adopt the format for anything that didn't make use of OCR.

As for Cez, well, that's another story entirely. Pills might actually help with that OCD :lol:

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3 months 6 days ago - 3 months 6 days ago #2202 by kitsunebi
Replied by kitsunebi on topic Problems with CBRs
Just so I don't have an army of torch-bearing hardcore PDF supporters track me down and set fire to my home, I want to make it clear that while it's true I wanted my own scans to be released in CBR since that's the format they were created for, I had nothing to do with Kiwi switching formats for the other releases (not directly, at any rate.) I've certainly defended CBR in the past as being a more open format and better than PDF should any further change or edit need to be made to the file after its initial creation, but those were simply facts. Which format is preferable for reading is of course an opinion, and I would never try to convince someone that their preference of reader was wrong.

Personally, regarding magazines, the reason I prefer CBRs is because they're an open format, allowing me to access the original jpgs if I need to without affecting their quality. But as for which format I prefer for reading magazines, I don't honestly care overly much (truthfully, I almost never read magazines anymore.) CBR or PDF, they both get the job done.

Comics are another matter, of course, and PDFs are woefully ill-suited for comics due to the way the pages are meant to be displayed and read. But since that's a fact rather than an opinion, it's never been a problem since comics simply aren't released in PDF format.
Last edit: 3 months 6 days ago by kitsunebi.

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3 months 2 days ago #2247 by Cez
Replied by Cez on topic Problems with CBRs
So I'm still trying to get my PDFs from CBRs and it just isn't working. Thank you for all you advice. I've wasted days on this trying out different settings but it doesn't seem to matter what I try. Either I lose an unacceptable amount of image quality or they are huge files (usually about three times the CBR). I was looking at some GamePro mags from Retromags. I downloaded the CBR and unzipped. At that stage I'm just looking at the images themselves right. So I stick it into PDF24 and create a PDF. Boom, its huge. Should my PDF software be compressing it to a more manageable file size? Going to go an cry in a corner now.

Oh and Kiwi, there aren't enough pills in the world... :)

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3 months 2 days ago #2248 by Cez
Replied by Cez on topic Problems with CBRs
The recently uploaded OPSX issue 24. Came in at about 250,000. I unzip it. I put the images through fotosizer to reduce to 300 dpi which I think Kiwi used to do. I then put them in to PDF24. Final PDF is 700,000 in size. I just don't get it. Think I'm going to have to go back to [GASP] Internet Archive. I'm joking of course. Although some good Edge supplements have been recently uploaded by DURian. Is he one of the bad ones that we don't like?

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3 months 2 days ago - 3 months 2 days ago #2251 by kitsunebi
Replied by kitsunebi on topic Problems with CBRs
I believe you're discovering one of the main drawbacks of the PDF format - it was initially created and designed as a proprietary format exclusive to Adobe. And while that's no longer the case, it remains true that the only way to really have satisfactory control over creating and editing PDFs is to use the paid version of Adobe Acrobat. I've never seen a free program that allowed for easy manipulation of a PDF file.

So that might be your problem right there.

The other problem, which I mentioned before, is that you keep changing the DPI for some reason? Why would you do that?
It's complicated and I don't want to rehash things I've already written about at CONSIDERATE length in the past in the Retromags forums, but briefly, DPI is a term related strictly to printing and refers to the number of ink dots per inch to be printed on a page. You can print a file at 300dpi, but you can't scan or save a file at 300dpi.

You CAN scan at 300ppi (pixels per inch) which is what we're actually talking about when discussing magazine scans. Once the scan has been made, though, it's best to just look at the PPI as just another way of expressing the image dimensions. You can't change the PPI of a scanned image without also changing its pixel dimensions - they are the same exact thing. If you have a 1000x1000 pixel image scanned at 600ppi and you reduce it by half to 300ppi, the image will also be reduced by half to 500x500 pixels. So please remember that changing the ppi (often mislabeled as dpi) is exactly the same as resizing the image.

So every time you've been changing the "dpi," you've been resizing the images. Was that your intent? If you were downloading someone's 600pppi RAW scans off of the Internet Archive, then resizing would almost definitely be a desired step (unless you LIKE your magazine files to be over 2GB each), but I would assume that you would have no reason to resize a file downloaded from either OGM (many of which are already saved at 300ppi) or Retromags or the Out of Print Archive (most of which are saved at less than 300ppi).



EDITED TO ADD: Oh, and yes, do you remember a while back when Kiwi announced the site was closing down? That was directly because of Durian. So, yes, he's definitely one of the BAD ones.
Last edit: 3 months 2 days ago by kitsunebi.

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3 months 2 days ago #2253 by Kiwi
Replied by Kiwi on topic Problems with CBRs

Cez wrote: The recently uploaded OPSX issue 24. Came in at about 250,000. I unzip it. I put the images through fotosizer to reduce to 300 dpi which I think Kiwi used to do. I then put them in to PDF24. Final PDF is 700,000 in size. I just don't get it. Think I'm going to have to go back to [GASP] Internet Archive. I'm joking of course. Although some good Edge supplements have been recently uploaded by DURian. Is he one of the bad ones that we don't like?


If I have 300mb of jpg images and I use Acrobat Pro to convert them to a PDF I get a 302mb PDF out of it so it sounds like the PDF24 app is your problem. Whether that is something to do with the settings in the app or just the way it functions when compiling the PDF I do not know but whatever the size of your base images combined are then it should remain pretty close to that.

The only reason I reduce images is if they PDF weighs in over 500mbs as I think they become too unwieldy above that size or pages are not the same size vertically so they look bad in two page viewing mode. If I do that though I only drop the vertical to whatever the smallest page is or to the nearest 10 pixels (e.g, if the smallest page is 3304px I might change it to 3300px for example) but I haven't really done that with any of Nipedley's PDF scans. And this problem disappeared with CDisplayEX so again nothing is done with his jpgs that I am aware of.

Of course there are always outliers where something needs to be done. For example, those PDF masters from the publisher for OPSX (UK)?
Well, they applied a different vertical and horizontal PPI rating. How the FUCK did they do that? As nothing I use gives me that option. So when I extract them to create the extra covers and CD inlays for our files I HAVE to specify a DPI extraction level (I use 600dpi) otherwise the resulting image is squashed in one direction.

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3 months 1 day ago #2261 by slider1983
Replied by slider1983 on topic Problems with CBRs
I too have gone to the Dark Side and am converting CBR files to PDF. I use a website online to convert the files. The files are definitely smaller in size and probably less sharp but that's the tradeoff I guess. :whistle:

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2 months 4 weeks ago #2282 by Kiwi
Replied by Kiwi on topic Problems with CBRs
Really old versions of Adobe Acrobat, if I recall correctly, used a print spooler (called Distliller) when changing files into a PDF. Later versions no longer use this and files are converted within the application itself. Looking at PDF24 which people seem to be using here to convert files, this uses a windows printer driver/spooler to generate the file. In other words, non-native conversion. I believe this app or the windows driver is not optimized and is causing your larger file sizes.

Using the online file conversion option in my opinion is just a dumb idea as they will be applying back end file compression to drop file sizes significantly and thus quality will suffer. You can do this with the offline version of PDF24 using the compression option but you get what you pays for, e.g, zero cost = less than stellar quality.

Short and long of it boils down to if you chose to use 3rd party apps accept the trade offs or find better software. Or just accept CBRs and use a decent program. The benefits I have come to realise simply outweigh staying with a proprietary format.

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2 months 3 weeks ago #2311 by slider1983
Replied by slider1983 on topic Problems with CBRs

Kiwi wrote: I believe this app or the windows driver is not optimized and is causing your larger file sizes.

Are you responding to me? I don't get larger file sizes, the opposite using the online PDF converter I use. It's certainly not perfect but it's alright I guess. If I can find a converter that keeps more quality therefore a file size closer to the original CBR file I'll go with that.

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2 months 2 days ago #2421 by Nipedley
Replied by Nipedley on topic Problems with CBRs
Speaking as a complete amateur here in terms of PDF, when I created my PDFs I used PDF-Xchange Tools. It has a lot of options and the PDFs come out at reasonable size - every PDF I created that was uploaded here was created with that software. It's not free, but it's a darn site cheaper than Acrobat Pro.

As to CBR/CBZ - That's definitely my preferred format. My workflow was always to create a PDF (using PDF-Xchange) for upload here/archive.org, and then zip the JPEGs up into a CBZ for my own usage. Now those CBZs get uploaded here too :-) I read mostly on a tablet using 'Perfect Viewer' and it does a great job. In terms of editing JPEGs that come out of those CBZs, I use XnView MP which has great batch editing options.

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2 months 1 day ago #2424 by Kiwi
Replied by Kiwi on topic Problems with CBRs
Technically, they are CBR's because I extract the images so I can edit the covers then RAR them back up into a CBR. I try and keep everything the same for my sanity :P

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2 months 21 hours ago #2427 by slider1983
Replied by slider1983 on topic Problems with CBRs

Kiwi wrote: Technically, they are CBR's because I extract the images so I can edit the covers then RAR them back up into a CBR. I try and keep everything the same for my sanity :P

Is there a way or program that will allow me to convert CBR to PDF but keep a similar quality?

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2 months 13 hours ago #2428 by Kiwi
Replied by Kiwi on topic Problems with CBRs
Acrobat Pro. Everything else are pretenders to the throne :P
The following user(s) said Thank You: slider1983

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2 months 11 hours ago #2429 by kitsunebi
Replied by kitsunebi on topic Problems with CBRs
The very question being asked here highlights the major flaw of PDF in regards to preservation.
CBR is just a file extension that flags the file for a CBR reader to open it, but it isn't an actual filetype. Despite the .cbr extension, the file is actually a RAR file, which itself is nothing but a lossless container full of jpgs. So a CBR file is really just a collection of JPGs.

Thus, what is really being asked here is "is there a way to turn jpgs into a PDF while keeping a similar quality?" And of course, the answer is YES, it's possible to turn JPGs into a PDF of "similar" quality without visibly noticeable degradation, but it is NOT POSSIBLE to turn JPGs into a PDF while keeping the EXACT quality, since the act of converting JPGs to PDF puts the JPGs (already a compressed format) through another layer of compression as they are re-encoded to the proprietary PDF format (at which point the original JPGs no longer exist and cannot be recovered.)

So for an endeavor such as digital preservation, where quality is a concern, it just makes more sense to deal in a format that preserves the original JPG images without re-encoding them as something else.

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2 months 3 hours ago #2430 by modgeezer
Replied by modgeezer on topic Problems with CBRs
Just curious since JPGs (already a compressed format) is there a lossless file format for images like flac is for music?

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2 months 2 hours ago #2432 by Kiwi
Replied by Kiwi on topic Problems with CBRs
TIFF is the accepted format for lossless images but file sizes are HUGE!!! There's no way you could realistically use them in a magazine. That is the way to store raw images if you wanted to create new files for one reason or another if you have the HDD space to store them. I cannot be bothered though....
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2 months 1 hour ago #2433 by kitsunebi
Replied by kitsunebi on topic Problems with CBRs
A 600ppi scan saved in TIFF is about 200 MB per page, so it's beyond impractical with a 200 page mag ending up around 40 GB. But everyone should feel free to upload as many 40 GB mags as they can to the Internet Archive. I'm sure they won't mind.

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1 month 4 weeks ago #2435 by modgeezer
Replied by modgeezer on topic Problems with CBRs
Thanks for the info

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